Expansible chuck for tubular core



March 11, 1969 c. D. LE HARDY 3,432,112

EXPANSIBLE CHUCK FOR TUBULAR CORE lof5 Sheet' Filed Aug. 10, 1967 INVENTQR CLEMENT 0. LeHARDY BY WWQ ATTORNEX March 1969 c. D. LE HARDY 3,432,112

EXPANSIBLE CHUCK FOR TUBULAR CORE Filed Aug. 10, 19s"! Shec 5 01's INVENTOR CL E MENT D. LeHARiDY ATTORNEY March 11, 1969 c. D. LE HARDY EXPANSIBLE CHUCK FOR TUBULAR CORE Sheet ,3 OfLB Filed Aug. 10, 1967 INVENTOR CLEMENT D. LeHARDY fm ATTORNEY United States Patent Office 3,432,112 Patented Mar. 11, 1969 3 Claims ABSTRACT OF THE DISCLOSURE An expansible chuck; which includes a stub shaft having an intermediate portion of polygonal cross sectional shape which underlies floating segments yielding urged radially outward into engagement with annular collars mounted on the shaft one of the collars being provided with means engageable with one end of a tubular core mounted on the chuck for positioning the core on the chuck in coaxial relationship with the shaft. The segments are provided with V-shaped inner surfaces engageable by apexes on the shaft intermediate portion upon relative movement between the shaft and segments so as to cam the segments radially outward into positive driving engagement with the core inner wall.

This invention is an improvement on the invention of the copending patent application entitled Explansible Chuck for Tubular Core, Ser. No. 586,430, filed by L. C. Wright on Oct. 13, 1966, and issued under Patent No. 3,355,121.

In many paper processing operations utilizing apparatus such as winders, rewinders, slitters and the like it has been proposed to provide stub shafts with expansible chucks which can be expanded into driving engagement with the inner wall of the paper roll core. By way of example, one common type of unwinding operation occurs in the newspaper industry wherein rolls of paper commonly referred to as newsprint are supported for unwinding by suitable means such as stub shafts inserted into each end of the paper roll core which is generally a paper tube. As the inner diameter of the paper core is subject to considerable variation resulting from excessive manufacturing tolerances, dimensional changes due to humidity, etc., the use of expansible chucks on such stub shafts has been suggested.

In the expansible chuck described and claimed in the aforementioned patent application, a stub shaft is provided having an intermediate portion of polygonal cross sectional shape which underlies floating segments yieldingly urged radially outward into engagement with annular collars mounted on the shaft. The segments are provided with V-shaped inner surfaces engageable by the apexes on the shaft intermediate portion upon relative movement between the shaft and segments so as to cam the segments radially outward into positive driving engagement with the inner wall of a tubular cone mounted on the chuck. The expansiblechuck of the aforementioned patent application substantially reduces or eliminates the disadvantages of prior chucks such as inadvertent destruction of the paper core wall, axial misalignment between the chuck and core, etc. However, even with the advantages obtained, some misalignment can occur to between the core and the chuck shaft as a result of the difficulty of maintaining the paper core in coaxial relationship with the chuck when the chuck is inserted within the end of the core. Such misalignment occurs primarily as a result of the weight of the paper roll which tends to move the upper segments closer to the shaft intermediate portion than the remaining segments.

Accordingly, a primary object of this invention is to provide a new and novel expansible chuck for a tubular core.

Another object of this invention is to provide a new and novel expansible chuck for a paper tube used in the winding and unwinding of sheet material which provides uniform driving engagement between the chuck and the tube inner wall.

A further object of this invention is to provide a new and novel expansible chuck for a paper tube which automatically positions the paper tube in coaxial relationship with the shaft incorporated with the chuck on which the tube is mounted.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings.

The objects stated above and other related objects in this invention are accomplished by the provision of an expansible chuck including a shaft having an intermediate portion of polygonal cross-sectional shape over which are positioned in overlying relationship a plurality of floating, circumferentially spaced segments. Each of the segments is provided with a V-shaped inner surface and means are provided for yieldingly urging the segments radially outward into engagement with collar means mounted on the shaft adjacent each end of the shaft intermediate portion. Means are provided on one of the collar means engagable with one end of a tubular core mounted on the chuck for positioning the core on the chuck in coaxial relationship with the shaft. Relative movement between the shaft and segments cams the segments radially outward into positive driving engagement with the core inner wall.

The novel features which are believed] to be characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a longitudinal sectional view of a chuck constructed in accordance with the invention together with a paper tu'be;

FIGURE 2 is a perspective view of a portion of the chuck of FIGURE 1;

FIGURE 3 is a view similar to FIGURE 1 showing the chuck of the invention;

FIGURE 4 is a sectional view partially broken away taken substantially along line 4-4 of FIGURE 3 in the direction of the arrows;

FIGURE 5 is an enlarged end view of the portion of the chuck shown in FIGURE 2; and

FIGURE 6 is an enlarged sectional View taken substantially along line 6-6 of FIGURE 5. As generally illustrative of the invention, there is shown in FIGURE 1 an expansible chuck constructed in accordance with the invention which has been designated generally by the letter C. The chuck C is arranged to be inserted in the wellknown manner into the end of a tubular core 11 such as a paper tube having an inner wall 12. The paper tube or core 11 is of the type which is generally wound with sheet material such as paper, film or the like and this sheet material may be newsprint from which newspapers are printed. In general, a pair of chucks C may be arranged in opposed relationship for insertion into the opposite ends of the core or tube 11 on which the sheet material is wound for an unwinding or winding operation only one of the chucks C being shown in FIG- URE 1 for clarity.

As shown in FIGURE 1, the chuck C includes a shaft 16 which in the illustrated embodiment is a shaft of relatively short length or what is generally referred to as a stub shaft. It should be understood that the chuck C of the invention may be of any suitable length throughout a wide range and that the length of the chuck shown in the drawings is representative of the chuck construction for any desired shaft length. For instance, the shaft 16 may be continuous extending completely through the tube The shaft 16 is provided with an intermediate portion 17 of polygonal cross sectional shape as shown best in FIGURE 4 and in the illustrated embodiment, the shaft intermediate portion 17 is of hexagonal cross sectional shape to provide six faces 18 with adjacent faces intersecting to define an apex 1811.

A plurality of circumferentially spaced segments are provided, preferably three in number identified by the numerals 21, 22 and 23, which are positioned freely in overlying relationship with the shaft intermediate portion 17. Each of the segments 21-23, which are identical in construction, is provided with a V-shaped inner surface 26, 27 and 28 having apexes 26a, 27a and 28a respectively, as shown in FIGURES 3, 4. Each of the inner surfaces 26-28 of the segments 21-23 corresponds to and is arranged in overlying mating relationship with a pair of adjacent faces 18 on the shaft intermediate portion 17.

The segments 21-23 are thus arranged for radial movement and collar means are mounted adjacent each end of the shaft intermediate portion 17 for limiting the radially outward movement of the segments. More specifically, the collar means include a front annular collar 31 and a rear annular collar 32, the front collar 31 being received within the paper tube 11 intermediate its ends and the rear collar 32 being located adjacent one end 11a of the tube 11 when the tube 11 is positioned on the chuck C.

In order to mount the front collar 31 on the chuck C, the collar 31 is provided with an inner bore 33 which receives a portion of reduced diameter 16a on the end of shaft 16. The collar 31 is preferably secured to the shaft 16 by suitable means as a set screw 36. The rear collar 32 is provided with an inner bore 34 for receiving the shaft 16 and the collar 32 is secured to the shaft 16 by suitable means such as a set screw 37. The collars 31, 32 are provided with inwardly projecting annular flanges 38, 39 respectively, under which opposite ends of the segments 21-23 extend as shown.

Means are provided on the outer surface of each of the segments 21-23 for frictionally gripping the inner wall 12 of the tube 11 when the segments are moved radially outward into driving engagement with the inner wall 12 of the tube 11. More specifically, the segments 21-23 are provided with longitudinally extending splines 41-43 respectively which project radially outward. The splines 41-43 terminate adjacent each end of the segments 21-23 respectively so as to extend between the collar flanges 38, 39 in the assembled position with the end portions of the segments extending below the collar flanges 38, 39.

Means are provided for yieldingly urging the segments 21-23 radially outward into engagement with the collar flanges 38, 39 and into uniformly spaced, parallel relationship with the shaft intermediate portion 17. More specifically, at least one spring is positioned between each of the adjacent longitudinal side edges of the segments 21-23 and in spreading engagement therewith. As described and claimed in the aforementioned copending patent application and as shown in FIGURE 4, a spring 44 is positioned between the longitudinally extending side edges 26b, 27b of the segments 26, 27 respectively with the ends of the spring extending Within an associated pair of oppositely disposed, aligned recesses 46 centrally arranged intermediate the ends of each of the segments. Only one of the springs 44 is shown in FIG- URE 4 for clarity, it being understood that the same spring arrangement is provided between the other longitudinally extending side edges of the segments as set forth in the aforementioned patent application.

As specifically illustrative of the invention, means are provided on one of the collars 31, 32 which is engageable with one end of the paper tube 11 mounted on the chuck C for positioning the paper tube 11 on the chuck C in coaxial relationship with the shaft 16. More specifically, as shown best in FIGURE 3, the rear annular collar32 is provided with an end portion 51 which is receivable within the end 11a of the paper tube 11 when the tube 11 is mounted on the chuck C as shown best in FIGURE 1. The collar end portion 51 is provided with a circumferentially extending outer surface 52 which is axially tapered radially outward in the opposite direction from the end portion 51 as shown. Thus, the tapered surface 52 is arranged to engage the inner wall 12 of the paper tube 11 adjacent the end 11a when the end portion 51 is received within the paper tube for positioning the paper tube 11 on the chuck C in coaxial relationship with the shaft 16.

FIGURES 2, 5 and 6 show clearly the rear annular collar 32 together with the end portion 51 and tapered outer surface 52. It will be noted that in the preferred embodiment, the tapered surface 52 includes a front portion 52a and a rear portion 5 211, the rear surface portion 52b being tapered to a greater extent that the front surface portion 52a as indicated by the angle a. Thus, when the paper tube 11 is inserted over the rear collar end portion 51, the tapered surface 52a produces a preliminary centering effect on the tube 11 relative to the shaft 16 which centering effect is increased substantially by means of the tapered portion 5212 as the chuck C is inserted completely within the end of the tube 1 1.

In the operation of the chuck C of the invention, the segments 21-23 are yieldingly urged radially outward by means of the springs 44 into the position shown in FIG- URE 3 with the ends of the segments in engagement with the collar flanges 38, 39 to limit further radially outward movement. As a result of the loading action of the springs 44, the segments 21-23 are maintained in uniformly spaced relationship about the shaft intermediate portion 17. When the chuck C is inserted into the end of the paper tube 11, the segments 21-23 move radially inward with the springs 44 forcing the segments 21-23 against the inner wall 12 of the tube 11 for positive driving engagement as a result of the biting or cutting of the splines 41-43 of the segments 21-23 respectively into the inner wall 12 of the tube 11.

As a result of the novel arrangement of this invention, any off-center relationship between the axis of the tube 11 and the axis of the shaft 16 such as might be produced from the downward force exerted by the weight of the tube 11 together with the sheet material wound thereon is compensated for as the collar end portion 51 moves into the end of the paper tube 11 as shown in FIGURE 1. As a result of the tapered surface 52 on the collar 32, the tube 11 is brought into coaxial relationship with the shaft 16 as the tube 11 moves over the shaft end portion 51 with the tube inner wall .12 adjacent the core end 11a sliding along the tapered surface 52.

It can be seen that there has been provided with the expansible chuck of the invention an improvement over the chuck of the aforemnetioned patent application. While a uniform engagement with the inner wall of the tube or core is provided with the chuck C of the invention, any tendency of the tube 11 to move oh? center relative to the shaft 1621s the chuck C is inserted within the tube end is compensated for as the novel arrangement of the rear collar of the chuck automatically moves the tube '11 into coaxial relationship with the shaft 16. It should be understood that although the chuck C of the invention has been shown in association with a plain paper tube, it functions equally as well with tubes having metal ends or sleeves inserted into each end of the tube.

While there has been described what at present is considered to be the preferred embodiment of the invention, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the invention.

Having thus described the invention, what is claimed is:

1. A chuck for a tubular core comprising, in combination, a shaft, an intermediate portion of polygonal cross sectional shape on said shaft, said intermediate portion having adjacent faces intersecting to form an apex, a plurality of circumferentially spaced segments freely positioned in overlying relationship with said shaft intermediate portion, each of said segments having a V-shaped inner surface corresponding to and arranged in overlying mating relationship with a pair of adjacent faces on said shaft intermediate portion collar means mounted on said shaft adjacent each end of said shaft intermediate portion for limiting radially outward movement of said segments, means for yieldingly urging said segments radially outward into engagement with said collar means and into uniformly spaced parallel relationship with said shaft intermediate portion, said apexes being arranged to engage said V-shaped inner surfaces on said segments upon relative movement between said segments and shaft intermediate portion to cam said segments radially outward into driving engagement with a tubular core mounted on said chuck and means on one of said collar means engageable with the end of said tubular core mounted on said chuck for positioning said tubular core on said chuck in coaxial relationship with said shaft.

2. A chuck in accordance with claim 1 wherein said positioning means including an end portion on said one collar means receivable within said tubular core one end, said end portion having a circumferentially extending outer surface axially tapered radially outward in the opposite direction from said end portion, said tapered surface being arranged to engage the inner wall of said tubular core when said end portion is received within said tubular core one end for positioning said tubular core on said chuck in coaxial relationship with said shaft.

3. A chuck in accordance with claim 1 wherein said collar means include a front annular collar and a rear annular collar mounted on said shaft adjacent each end of said shaft intermediate portion, said chuck being receivable within said tubular core to position said front annular collar intermediate the ends of said tubular core and to position said rear annular collar adjacent said tubular core one end, and wherein said rear annular collar includes an end portion receivable within said tubular core one end, said end portion having a circumferentially extending outer surface axially tapered radially outward in the opposite direction from said end portion, said tapered surface being arranged to engage the inner wall of said tubular core when said end portion is received within said tubular core one end for positioning said tubular core on said chuck in coaxial relationship with said shaft.

References Cited UNITED STATES PATENTS 999,191 7/1911 Hunter 24272 1,597,568 8/1926 Bandy 24268.2 2,113,701 4/1938 Mayer 24268.2 3,007,652 11/1961 Heckman 24272 3,355,121 11/1967 Wright 242682 NATHAN L. MINT Z, Primary Examiner. 

